This invention relates to a self-centering system. More particularly, this invention relates to a self-centering system for holding elongated objects in a manner which maintains their longitudinal axis in the proper orientation.
There are many situations where it is necessary or desirable to be able to hold or position an object and maintain proper orientation of the longitudinal axis of the object. For example, in many scientific instruments a vial or tube containing a sample to be tested must be inserted into the instrument at a specific location. It is also necessary to maintain proper orientation of the vial or tube in the instrument during the testing. For example, when the testing involves passing a light beam through the vial, the vial must be maintained in a proper location with respect to the path of the light beam (i.e. the vial must be centered with respect to the light beam).
Although various types of cell or vial holders have been previously used, none of them have the capability of automatically centering vials or cells of different diameters within a particular location in an instrument.
In accordance with the present invention there is provided a self-centering system for holding an object (e.g. a vial, tube or cell) to maintain the longitudinal axis in the desired orientation.
The self-centering system of the invention is especially useful in scientific instruments where a vial or cell must be supported in a vertical position and centered with respect to a particular location. For example, in some instruments which are currently used for optical testing, a separate sample cell holder must be used for each vial diameter. However, with the self-centering system of this invention, each different vial will be automatically centered in the holder so that the vial is in the proper position with respect to the path of the light beam.
In a preferred embodiment, the self-centering system comprises a pair of cam members which are each adapted to rotate about a horizontal axis. Tapered surfaces along the cam members enable the cam members to accommodate vials or tubes of different diameters. The cam members are interconnected (e.g. with meshing teeth members) so that when a vial or tube is inserted between the facing cam members, the surfaces of the two cam members rotate away from each other in a manner that the vial or tube remains properly centered between the cam members, regardless of the particular diameter of the vial or tube.
The self-centering system is adaptable to other types of objects besides vials or tubes (e.g. rods, wires, etc.).